Who you associate with is up to you of course. We all have a line (I'd be curious how many people here would happily associate with an active pedophile), so if bigotry is too disgusting for you to associate with then that is your line. Shouldn't force yourself to be friends with people that disgust you. 

But if we are bringing up moral honesty, I can't help but have the image of a person painfully cutting ties out of a sense of intellectual duty rather than emotional revulsion, or else "I don't want to cut this person out but because of X Y and Z it is my moral obligation to do so." That reasoning I have a problem, because it is too symbolic. If you cut somebody off, they are not going to change their minds. If anything it'll isolate them from the ideological soap necessary to clean their bullshit. Soo... what has happened? What was achieved? To me, the only reason for this would make sense would be A: if you somehow are enabling the immorality by knowing them. B: If you think there is a risk that you'll be too weak to avoid participation in the immorality. Anything else seems to be symbolic and therefore just a pointless exercise.